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Red sandstone with a strong water softening can cause difficulties of construction projects, especially for slope excavation and support engineering. Therefore, the study on the engineering properties of saturated red sandstone has a important meaning. The mechanical parameters of saturated red sandstone are obtained by the triaxial compression tests. The test results indicate that the ralations between peak strength, elasticity modulus and confining pressure for the saturated specimens are similar with the natural specimens, that is, with the increasing of confining pressure, the peak strength and the elasticity modulus will increase, but the growth rate becomes slowly. Under the same confining pressure, the peak strength and the elasticity modulus of saturated specimen are more smaller than the natural one. The mechanical damage caused by water recedes when the confining pressure increases, so for the geotechnical engineering with larger influence of water, the increasement of confining pressure by the supporting structures is conducive to the stability of rock mass. The research results will provide a theoretical basis for the red sandstone engineering. more...

Based on the analysis of a new type of air spring and the nonlinear finite element theory, this paper, taking the mechanical properties of the new type air spring into consideration, put forward an assessment method: the Mooney-Rivlin model with higher order term simulates rubber layer, the rebar model represents the cord thread layer, the stiffness of the listrium and the controllable damping shock absorber is rigid body, the gas flow and the pneumatophore are in coupling. In addition, the method has been tested and verified by applying to a new type vehicle air spring. This paper offers a new assessment method for the development of air springs in vehicle suspension. more...

In the quality assessment and classification of engineering rockmass, the elastic wave velocity of rockmass has already become an important parameter. But the valve of the elastic wave velocity has obvious anisotropy which is resulted from the non-uniformity characteristics of the rockmass. Therefore, if the measured elastic wave velocity is directly applied to the quality assessment of engineering rockmass, it will not can reflect the actual engineering properties of the rockmass. In order to solve the above problem, the energy variation of elastic wave propagating in the rockmass is studied. According to the field tests of the rockmasses with different weathering degrees, the dynamic characteristics of the elastic wave such as the attenuation and the dominating vibration frequency are analysed. The relationship between the kinetic parameters and the elastic wave velocities is researched. The results show that there is a good correlation between the kinetic parameters of the wave and the weathered rockmass, which can be applied to the rockmass quality classification and the engineering geology assessment. more...

The diffusion coefficient is one of the basic physical parameters of reflecting the property of wooden building materials, and it is the indispensable datum to calculate the dehydration time, estimate qualitatively the corrosion extent, provide the theoretical parameters for the protection technoiogy of the wooden building materials. The method of measuring diffusion coefficient of the wooden building materials is provided on the basis of Fick’s second law in this paper. The diffusion coefficient can be calculated using the given method by measuring the dehydration time, the initial water content and the stable water content after dehydration. The testing method is simple and feasible. Take a wooden materials for example, the experimental result is analyzed which indicates that the measurement method is reasonable. more...

Based on the test results, the wave velocity and the attenuation rule of elastic wave of weathered zone in Longmen Grottoes are studied. The wave velocity decreases with the increasing of the attenuation coefficient in a certain range. When wave velocity decreases to a certain value, there is not a relationship between wave velocity and attenuation coefficient. The attenuation coefficient thresholds of P-wave 0.01and S-wave 0.1 separate good rockmass quality from poor rockmass quality. The test results show that the elastic wave velocities of the surrounding rocks are generally high, which indicates that the rockmass skeleton is solid. But the rockmass anisotropy is obvious, which indicates that the structure planes are more developed. The results of the study are important for the protection of historical relics. more...